Field of Invention
The invention relates to a car battery, more particularly, to a car battery for a car ignition system.
Description of Related Art
Lead-acid batteries have been used for a long time. Lead-acid battery anodes are composed of lead the cathodes are composed of lead dioxide, and the electrolyte is a sulfuric acid solution of 27-39% capable of providing a voltage of 2.0 V. The lead-acid battery has several advantages, such as a high voltage potential, a wide operating temperature, a simplified structure, a well developed technology, a lower cost, and a longer cycling life. These advantages ensure lead-acid batteries play an important role in the battery industry worldwide. Over the past hundred years, the lead-acid battery has always been part of the standard equipment for a car ignition system.
However, the lead-acid battery also suffers from some vital disadvantages, such as raising the problems of serious pollution, a heavy weight and a limited lifespan. The lead-acid battery waste decomposes into a lot of heavy metals and wastewater thereby damaging ecological systems and threatening human health. The waste battery contains metal ions, such as mercury, lead, cadmium, chromium, nickel, and manganese etc, and an alkali or acid electrolyte solution. Once the pollutants enter the human body, the pollutants harm the nervous system, the hematopoietic function, the kidneys and bones. The weight of the lead-acid battery, such as a battery with a capacity of 65 Ah is about 15-20 kilograms. These batteries are, when considering their size and weight, inefficient energy produces resulting in a lot of energy wastage. The heavy weight of the lead-acid battery will, in the future, ensure it becomes an outdated component and eliminated from future car designs.
Besides, a lead-acid battery is incapable of performing a deep discharge, if the lead-acid battery performs a deep charge and discharge with about 70% of the capacity (a cycle), the lifespan of the battery will be shortened. Accordingly, the capacity of the lead-acid battery is desired within 60-80 Ah. The high output power of the lead-acid battery is also a factor of the heavy weight. To generate the high ignition current, the lead-acid battery must have an expanded capacity (by way of increasing battery weight).
Moreover, the lead-acid battery has problems of a shorten lifespan and a high self-discharging rate. If a deep discharge (80% of the capacity is discharged, if the driver forgets to turn off a car light) is performed, a new lead-acid battery must be implemented to replace the old one in about 1-2 years. The high self-discharging rate will cause the battery to totally run out of energy in about 2-3 months.
Accordingly, the vehicle industry needs an improved energy storage device for starting the ignition of a vehicle, and provides it for future electric cars.